Duke University Medical Center has established a laboratory for studying medical databases and their interaction with clinical investigation, teaching, and patient care. The goal of the laboratory is to develop new tools for the study of complex illness and to develop database systems suitable for actual use. During the past year, we have acquired appropriate hardware and achieved several of our intermediate goals. We have developed several new databases, made initial analyses of ambulatory EKG data, implemented a computer model for system evaluation and implemented a number of statistical procedures for comparing survival profiles in homogeneous subgroups. We will continue these activities in the coming year.